Add Mount Config to select use OsxFuse or Fuse-T

[labulakalia]

fuse/mount_darwin.go

Lines 409 to 419 in 2b0495a

	func mount(
	dir string,
	cfg *MountConfig,
	ready chan<- error) (dev *os.File, err error) {
	fusekernel.IsPlatformFuseT = false
	if fuset_bin, err := fusetBinary(); err == nil {
	return mountFuset(fuset_bin, dir, cfg, ready)
	}
	return mountOsxFuse(dir, cfg, ready)
	}

[stapelberg]

Can you explain why you need to work with both?

Can you send a PR to introduce an option?

cc @macos-fuse-t

[labulakalia]

@stapelberg i want to make some performance test for osxfuse and fuse-t，and free to choice